Abstract
The effect of retained austenite on hydrogen permeation behavior was investigated by electrochemical hydrogen permeation technique developed by Devanathan-Starchuski. The samples were extracted from seamless stainless steel tube water quenched after a solution treatment at 1000°C for 30min and heat treated at different tempering temperatures in order to achieve different contents of retained austenite. As a result, the concentration of retained austenite (γret) in martensitic-ferritic stainless steel affected the hydrogen diffusion and the retained austenite morphology showed a significant effect on hydrogen permeation. The lower hydrogen apparent diffusion coefficient (Dapp) was obtained for the sample called high retained austenite (HRA) with 22% of γret and the high solubility was obtained for the sample called medium retained austenite (RA).